RFID: What it is and how it works

Have you ever heard of radio frequency identification, or RFID for short? The term may frighten a little, but this is a very positive technology for society.

Although it was created in the 1940s, it is only now that more people are learning about this technology.

Among the individuals seeking to learn more about RFID, we can highlight shopkeepers and entrepreneurs in the commercial sector.

And you? Want to learn more about radio frequency identification and how it can help you profit more in your trade? Follow the next topics!

Pontos chave:

  • RFID significa Identificação por Radiofrequência. É uma tecnologia usada para identificar objetos anexando pequenos chips eletrônicos a eles. Esses chips contêm informações sobre o objeto ao qual estão anexados. Essas informações podem ser lidas por dispositivos chamados leitores.

  • Um sistema RFID é uma tecnologia para gerenciar seus itens já etiquetados, integrando leitores fixos (portais), móveis e etiquetas.

  • O RFID é um tipo de identificação que utiliza uma antena para transmitir informações por meio da radiação. Os códigos de barras são apenas algarismos numéricos que podem ser escritos em qualquer lugar.

Radio Frequency Identification (RFID)

The RFID (Radio Frequency Identification) system is a technology that has increasingly expanded its operations in various sectors. After all, this technology uses electromagnetic waves to access data that has been stored on a chip.

Thus, the RFID system has many benefits in identifying products and services by means of radio frequency. In addition, it is easy to use and fast in reading and transmitting data. It also integrates with other platforms and its use is flexible.

Therefore, this system is fundamental for companies, from production control to logistics management. And all this because it is efficient with respect to information identification. Thus, RFID is composed of:

  • Etiquetas (ou tags);
  • Antena;
  • Leitores.

So the reader reads the tag and transfers the information to the antenna. This system leads to less waste, reduces costs, and ensures the productivity and profitability of the company and its assets.

What is the function of RFID?

RFID technology – which we can also call radio frequency identification – is very important for some establishments.

The RFID system enables automated information capture. This can be of interest to allow the identification of objects by means of specific electronic devices.

These specific electronic devices that enable RFID solutions to function are called “electronic tags”, “electronic tags”, “RF tags”, or “transponders”.

These tags emit radio frequency waves, which travel to other devices that we call “readers”. We will talk more about these features in the next topics.

RFID System Cycle. Computer with Database, RFID Reader, RFID Antenna and RFID Tag
RFID System Cycle

What is an RFID system?

The name RFID comes from the English word “radio frequencyidentification”.

From the name, you may think that this is a technology far removed from our reality, that only scientists and great mathematicians know about and have access to.

However, if you think so, you are very wrong! RFID is a term that refers to any technology that uses radio waves to capture or transfer data.

RFID has been around since the mid-1940s, and is the technology that makes radios work. However, over time radio frequency identification has been improved for us to use in other ways.


How did the RFID system come about?

Radio frequency identification technology is one of the legacies of the technological development that took place during World War II.

Warring countries were already using radars based on radio waves. However, these radars could only detect the presence of troops, without being able to differentiate between allied and enemy troops.

In this context, German intelligence was able to discover that when their warplane pilots performed a certain maneuver, a change occurred in the radio wave they sent out.

Thus it was possible to differentiate allies from enemies from changes in the radio frequency signals sent. This was the first RFID system in history.

The RFID system and anti-theft technology

In commercial companies, RFID has already been used for decades as a theft prevention system.

In this environment, technology companies have created radio frequency tags, with the aim of identifying whether the customer has already paid for certain goods.

As a common example we have the big clothing department stores, present in malls all over Brazil.

In many of these stores, the clothes have tags that, if they pass through the door, transmit signals to readers that activate burglary alarms.

In this example, the employees pick up the tags at the cashier’s desk when paying. You certainly know what we are talking about!

RFID in Logistics

In logistics, the RFID system is very important and is popular among many companies. As an example, in inventory management and transportation of goods.

In the case of stocks, the products are tagged with information such as

  1. Categoria;
  2. Prazo de validade;
  3. Lote;
  4. Etc.

So when the product arrives in stock, workers can easily identify this information and speed up the organization.

Also, in freight transportation, we can install the RFID reader in the buckets of the trucks,

Such readers send to the system the information about which goods have passed through them to be delivered, what the delivery time is, among other information that facilitates logistics.

Read also: RFID technology for inventory management

Inventory Management with RFID

A company’s inventory is one of its most important parts. After all, this is where the company’s assets responsible for its working capital are stored. In addition, inventory information directly impacts many sectors of the company.

Therefore, it is essential that the stock is managed and the tools for this management are based on making it appropriate. In addition to producing information for the sectors involved.

Thus, there are numerous ways to perform inventory management. However, inventory management with RFID proves to be a faster and more reliable option with regard to errors in this management.

The RFID system uses microchip tags that are attached to products. Thus, these labels contain various pertinent information about each product, such as expiration and manufacturing dates, and barcodes.

However, labels alone would not be enough. The RFID system uses radio frequency to transmit all the information that the microchip labels display about the products.

This transmits all the information from the microchip by radio waves to an antenna. This integrates the information with the receiver that reads the information and transforms it into radio waves.

How much does it cost to install an RFID system?

To calculate the cost of installing an RFID system, we must consider the number of tags, the number and size of the readers, as well as the costs for the installation process itself.

To wit, a tag in the United States costs, on average, 25 cents, when bought together with a million chips.

In Brazil, however, the value rises to 80 cents to $1 for each tag.

In addition, it is necessary to measure the value of the other materials, such as antennas, computers, among others.

In addition, there is a cost for the actual installation and development of software that matches the customer’s needs. Even so, the biggest expense is usually the purchase of the tags.

Where do we use RFID?

Where do we use RFID?

We can use RFID technology in several contexts, but the best known is as a complement to barcode technology.

In addition, stores that use RFID technology to catalog their products can also use it to reduce theft, manage inventory, and even reduce waste.

Another advantage of RFID is that it can be the solution for establishments where bar code technology is not very effective.

In addition, radio frequency identification can be used to facilitate the coding of items that are present in large quantities in larger than normal stores.

How does the system work in an organization?

In an organization, the RFID (Radio Frequency Identification) system consists of two types of components: the readers and the tags (labels).

The tags are attached to the objects that will be identified in the future. The readers, in turn, receive the signals sent by the tags.

They can send these signals, for example, to a computer. This way, a person can read the information contained in the tag.

This information can be the value of the product, its date of manufacture or expiration, its status in the company, its classification, etc.

RFID for managing libraries

Did you know that it is possible to use RFID technology even in libraries? This is also an example of how this system can favor the logistics of an organization.

Books can be tagged with their editable information on the computer.

Thus, you can manage the books, and easily access records about past borrowings, category, age group, etc.

RFID in security systems

On top of all this, RFID technology – we can also call it radio frequency information – can contribute to security systems in protected areas.

Thus, we associate radio frequency information with the access control of these locations. Namely, the placement of doors with RFID readers that only open upon presentation of an object carrying a specific tag.

Furthermore, RFID technology can be applied, for example, as a way to revolutionize car alarms.

In this sense, the alarms are set to go off when they do not recognize a certain tag, present only in the car owner’s key.

RFID for animal control

RFID in Animal Identification

Did you think that the RFID system had no other use besides the many already mentioned above? You are wrong!

RFID technology renews itself over time, and with each passing year mankind finds ways to improve different systems by means of radio frequency information technology.

One innovative example is the use of tags on animals. The goal is to identify wild or domestic animals.

In the case of wild animals, identification helps in endemic control, animal studies, migration control, etc.

In the context of pets, the RFID system can be used to identify lost pets and return them to their owners.

Animals are biological assets and besides knowing that RFID technology can be used for animal identification and control, you can read our full article about it:


Ways of installing electronic tags on animals

As we saw above, labels are basically tags, which store important information.

This information is read by devices that we call “readers”, and these readers transfer the information to a screen, such as computers and cell phones.

But if we talk about putting these tags on animals, how can veterinarians or technicians do this? There are four ways of animal identification by the RFID system:

  1. Injetáveis: coloca-se a tag sob a pele do animal com instrumento especial;
  2. Colares: normalmente utilizados em animais dentro de uma organização, um ambiente fechado, pois é fácil de se perder;
  3. Ingeríveis: coloca-se a tag dentro de uma espécie de comprimido, e ela fica presa no estômago do animal durante anos;
  4. Brincos: são as mais baratas e podem ser lidas a curtas distâncias.

How is an RFID system maintained?

Every electronic system needs to go through a maintenance process periodically. In the case of radio frequency information systems, this is no different.

To do this, it is necessary to check the functioning of both the system tags and the readers.

If any errors or malfunctions are identified, the technicians must investigate the causes and work on solutions for such problems.

How feasible is the use of RFID in low-cost products?

In the case of low-value, low-profit products, switching from the bar code system to an RFID system may not be very advantageous.

This is because the value of putting up an RFID system is still not very low. Therefore, the tendency is for this substitution to happen first with high-margin products.

How do RFID tags work?

The tags, which we also call labels or transponders, are part of the radio-frequency identification system, which work together with the readers.

When the reader identifies the waves sent by the tag, it can decode the information loaded onto it. Then the reader transfers the information to a computer.

Tags are usually constructed of a small antenna and an electronic microchip. There are tags that have an internal battery, and others that are activated by the energy coming from the reader.

On this last type, the reader transmits an energy that reaches the tag by means of its antenna.

Which companies use RFID?

We often associate RFID technology with the commercial sector, because radio frequency information systems have great potential to replace barcodes.

However, we can use RFID systems in many different industries and sectors of the economy. Next, let’s talk about the practical uses of RFID technology.

RFID in the industrial sector

As for the industry sector, the transportation area is the most prominent in the use of RFID readers. They are used, for example, on tolls, in airplane luggage, and in rented vehicles.

At the toll booths, instead of the driver having to stop every time to pay, RFID readers capture how many times the vehicle has passed by during a month.

This capture is accomplished thanks to the tags present in the vehicles. At the end of the month, the driver receives a bill to pay for all the times he has passed through the tolls.

In the case of airlines, tags can be placed on the luggage so that readers can identify it more easily and direct it to the correct place. This avoids delays and makes the service more efficient.

RFID in chemical industries

In addition, we can talk about the identification of containers in factories. These containers hold produced materials, ingredients, or even intermediates.

Usually, barcodes are used in this case. However, when containers provide reagents for chemical reactions, a higher degree of accuracy of the information is required.

Therefore, the radio frequency information technique is the most suitable in such cases. In addition, the tags are better able to withstand temperature changes, radiation, dust, and mechanical impacts.

RFID in the commercial sector

In the commercial sector, RFID is often used for buying and selling products.

In this context, tags are installed on products still in the factories and the readers can be configured, for example, on cell phones.

So the salespeople can simply point their cell phones at the products in the store and access all the information present in the tags.

This facilitates and expands the possibility of selling that particular product, because the customer does not have to wait too long for the employee to answer all his questions about the merchandise.

We also use RFID technology to facilitate credit card purchases, where the readers send the purchase request to the card companies after reading the tag on the buyer’s card.

RFID system outlook for the future

Despite having emerged in the mid-1940s during World War II, the RFID system continues to evolve.

The outlook for the future of radio frequency information technology includes several areas, mainly involving the miniaturization of tags and readers.

Even though it is already possible to design very small readers and labels, for some purposes it may be necessary that these devices are not perceived by human touch or taste.

It is estimated that RFID technology can contribute to the process of targeted marketing, for automatic payment in stores, implants in humans, biometric passports, etc.

How will technologies like RFID impact inventory management processes? What are the advantages of using RFID?

RFID technology certainly has many benefits for both business owners and customers.

Firstly, with this technology it is possible to read information without physical contact, that is, at a certain distance between tag and reader. This facilitates and speeds up data analysis and enables social distancing when necessary.

In addition, the information storage capacity on labels is very large in relation to the size they can assume.

These labels are also reusable, extremely durable, and accurate in the information they carry.

Another advantage of the radio frequency information system is its wide-ranging ability to function as a theft and counterfeit prevention system.

Finally, we need to point out that the cost of installing this system has decreased over time.

What are the main problems related to RFID technology?

Even though it is a very innovative technology loaded with potential benefits for many different purposes, there are some problems surrounding radio frequency information technology.

The first problem is the high cost of the RFID system when compared to the cost of installing a barcode system.

Another problem is that with materials made of metal, there can be interference with the site’s magnetic field.

This interferes with the radio frequency signals and can limit the operation of the system readers in this context.

Furthermore, product information can be leaked, since any reader placed towards a certain product can read the label, even if it is not connected to the company that placed it.

Finally, we mention the possible invasion of customer privacy through frequent monitoring of the products purchased.

How to try to solve the problems of the RFID system?

We have just talked about some disadvantages presented by the RFID, or radio frequency information system.

However, don’t worry! Possible solutions already exist to at least alleviate the problems described in the previous topic. Some of the possible solutions are:

  1. Dispositivos metálicos: Alguns estudos indicam que, caso envolvamos a etiqueta com uma capa de material reflexivo, essa tag pode ficar livre das interferências externas.
  2. Criptografia: Algumas plataformas digitais, como e-mail e WhatsApp já utilizam a criptografia. Ela permite que apenas o leitor e o receptor consigam ter acesso à informação. Se algum terceiro tentar acessar essa informação, precisará decifrar um código bastante complexo.
  3. Códigos: Os códigos funcionam como senhas para que o leitor do sistema RFID execute sua função.
  4. Zombie RFID tag: Traduzindo para a Língua Portuguesa, o nome seria “tag zumbi”. Ela funciona assim: após o pagamento, o produto passa por um dispositivo que “desliga” a tag temporariamente. Assim, o cliente pode levar seu produto para a casa, mas caso alguém tente ler as informações RFID, não conseguirá. Se o cliente devolver o produto, este pode passar pelo mesmo dispositivo especial para reativar a etiqueta de radiofrequência.
  5. Conscientização dos consumidores: Avisar os consumidores acerca da presença de tags de RFID nos produtos e incentivá-los a proteger os dados presentes nas tags.
  6. Uso correto das tags: Para evitar vazamento de informações, o ideal seria que as lojas desativarem as tags no ato da venda, além de posicioná-las na embalagem do produto, e não no produto em si. Assim, fica mais fácil o descarte. Além disso, as tags devem ser visíveis e de fácil retirada.

Differences between RFID and Barcode technology

We are talking about how RFID technology has the potential to replace the bar code, as well as its application in other contexts.

However, why would it be so advantageous to slowly make this substitution happen?

Let’s talk now about the main differences between RFID, radio frequency information technology, and the bar code, which everyone knows.

First of all, the barcode is not very resistant to mechanical shocks and can easily be erased by friction. The RFID tag, on the other hand, is very resistant to this factor.

Also, the information security guarantee of the barcode is low, but tests claim that the RFID system is much more secure in this respect.

Although the initial cost for the installation of RFID is higher than for barcoding, the maintenance cost of RFID is low compared to the other technology.

What is the main characteristic of a passive RFID tag?

In the RFID system, we have the presence of tags, which work as information “labels”, and the readers, which decode this information.

Some tags attach themselves to small batteries, which provide them with the energy they need to function.

However, most tags do not have these batteries. So they rely on the signal sent by the reader to send energy to the tags and thus activate them.

When a tag is deactivated and therefore not sending the information in it, we classify it as a “passive tag”.

How to track an RFID?

In order to track an RFID system, you need to use equipment called “readers”.

The readers can identify the radio waves sent by the tags, which we also call “electronic tags”.

There also needs to be an interface connected to this reader, such as a computer, cell phone, or tablet.

The interfaces serve to receive the information read by the reader and present it in a decoded form available for identification.

RFID Antenna

RFID antennas are one of the essential devices for the RFID system to work properly and achieve its objective. Thus, they are responsible for transmitting and receiving information by means of electromagnetic waves or radio frequency signal.

So the RFID antenna is responsible for the communication between RFID tags and their reader devices. In this way, it will transmit the information contained in one to the other.

In addition, this antenna is installed in a strategic location where it cannot be accessed by the user and will provide radio frequency signal coverage.

Therefore, the RFID antenna is essential for the company, because its main function is to transmit and capture information. For without them, the RFID system does not work, let alone achieve its goal of transmitting information quickly and in a time-efficient manner.


RFID tags are made of various materials, but they need to have the technology to conduct the information to the antenna. In addition, they come in various sizes and can be active or passive. And this to suit the product and the company’s needs.

Therefore, it is these labels that allow, by their identification, the counting of products in a much shorter time than manual counting. Besides there does not need to be a partial inventory.

This means that by the RFID system, there is the possibility to track the tags and their information anywhere. Whether it is inside the warehouse, on the way to the delivery, or during the delivery. In a way that is completely practical and efficient to read.


RFID Reader

The RFID tag reader is another essential device for the correct functioning of RFID technology. This reader is a device that reads the RFID tags and collects the information available on it. Thus, the transfer of information is by means of radio waves that act between the data on the label and the reader.

Through the tag reader it is possible to track the assets and everything on their tags. However, this reading does not have to be done directly, since the reader can be within a radius of 90 to 900 centimeters to absorb all the information.

Therefore, the RFID tag reader can be considered the brain of the RFID system, as it is essential for this technology to work. After all, it is through the readers that information is transmitted and received from the RFID tags.

RFID and contactless payment

RFID has a technology that allows information to be collected within a certain range. In this way, there is no need to be close or even have contact with the objects that have the information.

Therefore, RFID is an alternative technology to the barcode reading method. So that RFID optimizes time for a company in relation to its products. But also assist with reading personal documents and internet or card payments.

Thus, debit and credit cards have increasingly adapted to RFID. Thus, payments do not need to have physical contact between machines and cards to make payments. For the machines scan the information through an identification chip.

So contacteless technology is one that enables financial transactions to happen by proximity. No need to insert the card to the card machine. For, the reading of the data and information occurs by the approximation between the two.

Through technology, there is a connection, by radio frequency, between the cards and the card machines. The cards have RFID technology and the machines, NFC. With this, contactless payment enables quick and easy payment.

What blocks RFID? / How to block RFID signal

One of the concerns of companies is the possibility of blocking the RFID signal. With this blocking, the system stops working and does not achieve its goal of transmitting data and information.

So even though they are illegal, there are several devices that block or limit the range of the RFID signal being sold on the internet. And this worries institutions and people because criminals can access the data and steal the information.

For one of the vulnerabilities of RFID reading equipment is the possibility that criminals can use it. So that they use distance to steal personal and financial information without the person knowing.

Thus, these devices limit the functions of the tag readers by blocking the communication between them and the RFID chips.

In addition to devices, there are also home-made solutions with RFID reading blocking capabilities. Thus, they are materials that have carbon or aluminum fibers in their composition.

How does RFID protection work?

Even if contactless payment by means of RFID is practical and technological, there is a disadvantage. Which is about the security of the user’s data, financial and personal.

However, technology security companies have not yet developed any systems that intercept hacker attempts. Thus, people had to look for alternatives to circumvent the vulnerability of having their data hacked.

So while technology companies are not developing encryption, people are opting for more homemade solutions. For example, there are companies and people selling and making wallets that promise to protect against data scams by reading RFID.

So these wallets are made of leather, but have aluminum shielding in the polyester lining. And it is the aluminum that makes sure that hacker interceptions of financial and personal data do not occur.

Because radio frequency waves are easy to disrupt, aluminum shielded wallets are a great alternative.

Thus, they are the best form of RFID protection by covering the cards with materials that interfere with the radio waves. In order to block the electromagnetic field and bar the communication between the cards and the RFID readers.

Now it’s up to you! Did you enjoy the reading? Did you already know about radio frequency information technology? Comment below what you thought! We want to know what you think.

Frequently asked questions:

How to choose the type of label?

This is the most important decision, because for each type of industry, we have a suggestion of TAGs or Labels.

This is the great differential of having a manufacturer and applicator of the solution on your side, at the moment of decision.

Can I use RFID on metallic goods?

Yes. CPCON has labels that have high performance on metal surfaces.

Do I need to invest in antennas?

Antennas are used in processes where there is a need to control the large-scale input and output of items. Generally, for asset control, this investment is not necessary, since the collectors already have high-spectrum antennas and reading distance, and the fixed asset inventory processes are
totally different from inventory control, for example.

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